HID: core: prevent out-of-bound readings

[pandora-kernel.git] / drivers / hid / hid-core.c

diff --git a/drivers/hid/hid-core.c b/drivers/hid/hid-core.c
index 6726706..1ec8825 100644 (file)
--- a/drivers/hid/hid-core.c
+++ b/drivers/hid/hid-core.c
@@ -218,9 +218,9 @@ static int hid_add_field(struct hid_parser *parser, unsigned report_type, unsign
 {
        struct hid_report *report;
        struct hid_field *field;
-       int usages;
+       unsigned usages;
        unsigned offset;
-       int i;
+       unsigned i;
 
        report = hid_register_report(parser->device, report_type, parser->global.report_id);
        if (!report) {
@@ -239,7 +239,8 @@ static int hid_add_field(struct hid_parser *parser, unsigned report_type, unsign
        if (!parser->local.usage_index) /* Ignore padding fields */
                return 0;
 
-       usages = max_t(int, parser->local.usage_index, parser->global.report_count);
+       usages = max_t(unsigned, parser->local.usage_index,
+                                parser->global.report_count);
 
        field = hid_register_field(report, usages, parser->global.report_count);
        if (!field)
@@ -250,7 +251,7 @@ static int hid_add_field(struct hid_parser *parser, unsigned report_type, unsign
        field->application = hid_lookup_collection(parser, HID_COLLECTION_APPLICATION);
 
        for (i = 0; i < usages; i++) {
-               int j = i;
+               unsigned j = i;
                /* Duplicate the last usage we parsed if we have excess values */
                if (i >= parser->local.usage_index)
                        j = parser->local.usage_index - 1;
@@ -753,7 +754,17 @@ struct hid_report *hid_validate_values(struct hid_device *hid,
         * ->numbered being checked, which may not always be the case when
         * drivers go to access report values.
         */
-       report = hid->report_enum[type].report_id_hash[id];
+       if (id == 0) {
+               /*
+                * Validating on id 0 means we should examine the first
+                * report in the list.
+                */
+               report = list_entry(
+                               hid->report_enum[type].report_list.next,
+                               struct hid_report, list);
+       } else {
+               report = hid->report_enum[type].report_id_hash[id];
+       }
        if (!report) {
                hid_err(hid, "missing %s %u\n", hid_report_names[type], id);
                return NULL;
@@ -978,6 +989,7 @@ static void hid_input_field(struct hid_device *hid, struct hid_field *field,
                /* Ignore report if ErrorRollOver */
                if (!(field->flags & HID_MAIN_ITEM_VARIABLE) &&
                    value[n] >= min && value[n] <= max &&
+                   value[n] - min < field->maxusage &&
                    field->usage[value[n] - min].hid == HID_UP_KEYBOARD + 1)
                        goto exit;
        }
@@ -990,11 +1002,13 @@ static void hid_input_field(struct hid_device *hid, struct hid_field *field,
                }
 
                if (field->value[n] >= min && field->value[n] <= max
+                       && field->value[n] - min < field->maxusage
                        && field->usage[field->value[n] - min].hid
                        && search(value, field->value[n], count))
                                hid_process_event(hid, field, &field->usage[field->value[n] - min], 0, interrupt);
 
                if (value[n] >= min && value[n] <= max
+                       && value[n] - min < field->maxusage
                        && field->usage[value[n] - min].hid
                        && search(field->value, value[n], count))
                                hid_process_event(hid, field, &field->usage[value[n] - min], 1, interrupt);
@@ -1284,7 +1298,7 @@ int hid_connect(struct hid_device *hdev, unsigned int connect_mask)
                "Multi-Axis Controller"
        };
        const char *type, *bus;
-       char buf[64];
+       char buf[64] = "";
        unsigned int i;
        int len;
        int ret;